From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754451Ab1KJRZd (ORCPT ); Thu, 10 Nov 2011 12:25:33 -0500 Received: from e3.ny.us.ibm.com ([32.97.182.143]:32948 "EHLO e3.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751192Ab1KJRZc (ORCPT ); Thu, 10 Nov 2011 12:25:32 -0500 Date: Thu, 10 Nov 2011 09:22:56 -0800 From: "Paul E. McKenney" To: Peter Zijlstra Cc: Josh Triplett , linux-kernel@vger.kernel.org, mingo@elte.hu, laijs@cn.fujitsu.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@polymtl.ca, niv@us.ibm.com, tglx@linutronix.de, rostedt@goodmis.org, Valdis.Kletnieks@vt.edu, dhowells@redhat.com, eric.dumazet@gmail.com, darren@dvhart.com, patches@linaro.org Subject: Re: [PATCH RFC tip/core/rcu 05/28] lockdep: Update documentation for lock-class leak detection Message-ID: <20111110172256.GD2354@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <20111102203017.GA3830@linux.vnet.ibm.com> <1320265849-5744-5-git-send-email-paulmck@linux.vnet.ibm.com> <20111103025716.GA2042@leaf> <20111103194226.GG2287@linux.vnet.ibm.com> <1320847328.19727.2.camel@twins> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1320847328.19727.2.camel@twins> User-Agent: Mutt/1.5.20 (2009-06-14) x-cbid: 11111017-8974-0000-0000-000001C82637 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 09, 2011 at 03:02:08PM +0100, Peter Zijlstra wrote: > On Thu, 2011-11-03 at 12:42 -0700, Paul E. McKenney wrote: > > > If so, could we simply arrange to have lockdep scream when it encounters > > > an uninitialized spinlock? > > > > I reworded to distinguish between compile-time initialization (which will > > cause lockdep to have a separate class per instance) and run-time > > initialization (which will cause lockdep to have one class total). > > Right, runtime init will key off of the call-site, compile-time init > will key off of the static data address. > > > Making lockdep scream in this case might be useful, but if I understand > > correctly, that would give false positives for compile-time initialized > > global locks. > > Yeah, that's going to bring a lot of pain with it, in particular all the > early stuff like the init task etc. are all statically initialized. OK, will stick with the current approach, then. Thanx, Paul